6698
J. Org. Chem. 1992,57,6598-6603
KzCO3 (35 mg, 0.25 mmol), and MeOH (1.5 mL) was stirred for 19 h. The product was isolated in the usual way and chromatographed @ioz, 1.5 g, 100-200 mesh, toluene-acetone) to give aldehyde 4 (34 mg, 85%) as colorless oik [a]'$ +3.5" (c 2.14). NMR spectra of this product are identical with those of 2. (2R,3R)-2,30-1eopropylidene-4-0-(triphenylmethyl)erythrose (3). A solution of thioacetal 17 (152 mg, 0.274 "01) in CHzClz(2 mL) was treated with DIBALH (1 M in hexane, 0.9 mL) at -78 "C for 1 h. Workup and chromatography of the crude product @ioz, 2 g, toluene) gave aldehyde 3 (74 mg, 67%): mp 120-122 OC (acetonehexane); [a]lgD+87.5" (c 2.08). The NMR spectra of this product are identical with those of 1. (2R,3R)-L,l-Bis(phenylthio~butane-2,3,4-triol Triacetate (18). (a) From D-(-)-Erythrose (19). A mixture of D-(-1erythrose (88 mg),benzenethiol(O.5 mL), and concd HCl(O.5 mL) was stirred for 18 h. Solid CaC03 was added, and the mixture was diluted with MeOH (10 mL) and filtered. The filtrate was evaporated in vacuo. The residue was washed with hexane and dried whereupon it was treated wit pyridine (1 mLJ, AqO (1 mL),
and DMAP (10 mg) for 30 min. Workup and chromatography (SiOz, 5 g, toluene-acetone) gave the derivative 18 (76 mg) as colorless oik [a]"D +58.5" (c 1.91); IR (film) 1755 and 1220 (acetate) cm-'; NMR b~ 1.93, 2.00, and 2.01 (3 a, 3 each, CH3), 4.16 (dd, 1, J = 4.8,12.5 Hz, C4Ha), 4.34 (dd, 1, J = 2.7,12.5 Hz, Cd Hb), 4.50 (d, 1, J = 3.4, C1 H), 5.50 (dd, 1, J = 3.4,7.6 Hz, Cz H), 5.59 (ddd, 1, J = 2.7,4.8,7.6 Hz, C3 H), 7.2-7.6 (m, 10, arom H); bc 20.25, 20.36,20.46 (Me), 61.3,61.8 (Cl, C4),70.5, 72.4 (Cz, C3), 128.3, 128.5 (CJ, 129.2 (Cm),132.8, 133.7 (Co),133.8, 134.5 (Ciw), 169.7, 170.7 (CO). Anal. Calcd for CzzHz406Sz (448.53): C, 58.91; H, 5.39; S, 14.30. Found C, 59.13; H, 5.47; S, 14.16. (b) From Compound 3. A mixture of aldehyde 3 (47 mg), benzenethiol(O.25mL), and concd HCl(0.25 mL) was stirred for 14 h and worked up as described above. The crude product was treated with pyridine (0.2 mL), AqO (0.2 mL),and DMAP (3 mg) for 2 h. Workup and chromatography @ioz, 1 g) of the crude product gave acetal 18 (40mg,76%)as colorless oil: [a]'$ + 63.1" (c 2-06), showing the same spectral properties as the product described under a.
Reactions of Carbonyl Compounds with [(Trimethylsilyl)propargyl]diisobutyltelluroniumBromide Mediated by Different Strong Bases: Highly Regioselective Synthesis of (Trimethylsily1)propargyl Alcohol and Highly Stereoselective Synthesis of cis - (Trimethylsilyl)alkynyl Epoxides7 Zhang-Lin Zhou, Yao-Zeng Huang,* Li-Lan Shi, and Jiong Hu Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Academia Sinica, 345 Lingling Lu, Shanghai 200032,China
Received January 14, 1992 [ (Trimethylsilyl)propargyl)]diisobutyltelluronium bromide (l),after being treated with alkyl- or aryllithium reagent, undergoes a lithium-tellurium exchange reaction via an unstable transient tetraorganyltellurium intermediate, and the in situ generated lithium species reacts with carbonyl compounds to give (trimethylsily1)propargyl alcohols 2 in high yields with high regioseledivity. However, when the telluronium salt 1 was treated with nonnucleophilic basea such as LDA or lithium 2,2,6,6tetrmethylpiperidide,the moderately stabilized silylated telluronium ylide formed. The silylated telluronium ylide reacted with carbonyl compounds to afford (trimethylsily1)alkynyl epoxides ll in good to excellent yields with high cis stereoselectivity.
Recently there has been a remarkable interest in the synthetic application of organotellurium reagents.' With the development of sulfonium, sulfoxonium, and selenonium ylides? the application of several stabilized and moderately stabilized telluronium ylides in organic synthesis has been de~cribed.~In our previous paper, we found that diphenyltelluronium methylide-the first nonstabilized telluronium ylide generated from methyldiphenyltelluroniumtetraphenylborate-reacted with aldehydes or ketones to form substituted oxiranes.4 However, the reactions of trimethyl- and methyldiphenyltelluronium salts (precursors of nonstabilized telluronium
ylides) with aromatic aldehydes gave secondary alcohols with the use of alkyl- or aryllithium reagent.5 Later, we reported that the reactions of carbonyl compounds with benzyldibutyltelluronium bromide (precursor of semistabilized telluronium ylide) and dibutyl(cyanomethy1)telluronium chloride (precursor of stabilized telluronium ylide) afforded homobenzylic alcohols and &hydroxy nitriles respectively promoted by alkyl- or aryllithium 'This paper is the 100th report on the application of elementoorganic compounds of 15th and 16th groups in organic synthesis. For the 99th report and preliminary communication, see: Zhou,2. L.; Huang,Y. Z.;Shi, L. L. J. Chem. Soc., Chem. Commun. 1992,986. 0022-3263/92/1957-6598$03.OO/0
reagent6 However, no report concerning the synthesis and reactions of a silylated telluronium ylide has appeared in the literature. We wish to report herein that reactions of carbonyl compounds with [ (trimethylsilyl)propargyl]di(1) (a) Irgolic, K. J. The Organic Chemistry of Tellurium; Gordin and
Breach Science: New York. 1974. (bl Uemura. 5. Kanaku 1981.36.381. (c) Engman, L. Acc. Chem: Res. 19SS,18, 274: (d) Petragnani; N:; Comasseto, J. V. Synthesis 1986, 1. (e) Back, T. G. The Chemistry of Organic Selenium and Tellurium Compounds;Patai, S., Ed.; Wiley New York, 1987; p 2. (0Engman, L. Phosphorus Sulfur 1988,38, 105. (g) Petragnani, N.; Comasseto, J. V. Synthesis 1991, 793, 897.
(2) (a) Trwt, B. M.; Melvin, L. S., Jr. Sulfur Ylidea; Academic: New York, 1975. (b) Dumont, W.; Bayet, P.; Krief, A. Angew. Chem., Int. Ed. Engl. 1974,13,274. (c) Clive, D. L. J. Tetrahedron 1978,34, 1049. (d) Takaki, K.; Yasumura, M.; Negoro, K. Angew. Chem.,Znt. Ed. Engl. 1981, 20, 671. (3) (a) Osuka, A,; Mori, Y.; Shimizu, H.; Suzuki, H. Tetrahedron Lett. 1983, 24, 2599. (b) Osuka, A.; Suzuki, H. Tetrahedron Lett. 1983, 24, 5109. (c) Osuka, A.; Hanasaki, Y.; Suzuki, H. Nippon Kagaku Kaishi 1987, 1505. (d) Huang, X.; Xie, L. H.; Wu,H. J. Org. Chem. 1988,53, 4862. (e) Zhou, Z. L.; Sun, Y. S.; Shi, L. L.; Huang, Y. Z.J. Chem. Soc., Chem. Commun. 1990, 1439. (f) Zhou, Z. L.; Shi, L. L.; Huang, Y. Z. Tetrahedron Lett. 1990, 31, 7657. (4) Shi, L. L.; Zhou, Z. L.; Huang, Y. Z. Tetrahedron Lett. 1990, 31, 4173. (5) Shi, L. L.; Zhou, Z. L.; Huang, Y. Z. J. Chem. Soc., Perkin Trans. I 1990,2847. (6) (a) Li, S. W.; Zhou, Z. L.; Huang, Y. Z.; Shi, L. L. J. Chem. SOC., Perkin Trans. 1 1991, 1099. (b) Zhou, Z. L.; Shi, L. L.; Huang, Y. Z. J. Chem. SOC.,Perkin Trans. 1 1991, 1931.
0 1992 American Chemical Society
Reactions of Carbonyl with Telluronium Bromide
J. Org. Chem., Vol. 57, No. 24, 1992 6699
isobutyltelluronium bromide (1) (precursor of silylated telluronium ylide) mediated by lithium 2,2,6,6-tetramethylpiperidide (LiTMP) give cis-(trimethylsily1)alkynyl epoxides in excellent yields, while those mediated by alkylor aryllithium reagent afford (trimethylsily1)propargyl alcohols in high yields. In the last decade, unsaturated organmilicon compounds have been extensively studied because of their interesting potential in selective organic synthesis.' Thus vinylJ and dienylsilane~~ have received much attention and their synthetic utility has been demonstrated in numerous carbon-carbon bond forming reaction. Alkynyltrimethylsilanes are also an important class of compounds and many useful transformations have been reported.1° 3-Bromo-l-(trimethylsilyl)-l-propyne could be easily prepared from propargyl alcohol by treatment with 2 equiv of ethylmagnesium bromide and chlorotrimethylsilane, followed by bromination with phosphorus hibromide." It reacted with diisobutyl telluride without solvent at room temperature under nitrogen to give [3-(trimethylsilyl)-2propynyl]diisobutyltelluronium bromide (1) in 87% yield (eq 1). i-BbTe
+
Me3SC=CCH2Br
Table I. Highly Regioselective Synthesis of (Trimethylsilyl)DroDareY1Alcohols 2 entry 2 3
4 5 6 7 8 9 10 11 12 13 14
rt
OH
I
+ i-B&Te+R Br-
(1)
'
2
Attempts to generate the silylated telluronium ylide by alkyl- or aryllithium reagent, similar to that of corresponding phosphonium and arsonium ylide, failed.12 It was reported that the reactions of aldehydes and ketones with [3-(trimethylsilyl)-2-propynylidene]triphenylphosphorane and -arsorane, generated in situ from the corresponding phosphonium and arsonium salts, reapectively, with n-butyllithium, gave terminal trimethylsilyl enynes.12 However, the telluronium salt 1, after being treated with alkyl- or phenyllithium, reacted with carbonyl compounds to give alcohols, viz. l-substituted-44trimethylsilyl)-3-butyn-l-ols2 in excellent yields (eq l), instead of the corresponding alkenes or epoxides, the products expected by analogy with the reactions of other heteroatom ~1ides.l~ (7) (a) Colvin, E. W. Silicon Reagents in Organic Synthesis; Academic Prese: London, 1988. (b) Colvin, E. W. Silicon in Organic Synthesis; Butterworthe. London, 1981. (c) Weber, W. P. Silicon Reagents for Organic Synthesie; Springer-Verlag: Berlin, 1983. (d) Fleming, I. Chem. SOC.Rev. 1981, IO,83. (e) Chan, T. H.; Fleming, I. Synthesis 1979,761. (0Andreini,B. P.; Carpita, A.; h i , R.; Scamuzzi, B. Tetrahedron 1989, 45, 5621. (8) (a) Miller, R. B.; McGarvey, G . J. Org. Chem. 1979,44,4623. (b) Westmijize, H.; Kleijn, H.; Vermeer, P. J. Organomet. Chem. 1984,276, 317. (c) Hatanaka, Y.; Hiyama, T. J. Org. Chem. 1989, 54, 268. (d) Fleming, I.; Dunogues, J.; Smithers, R. Org. React. 1989, 37, 57. (9) (a) Carter, M. J.; Fleming, 1.; Percival, A. J. Chem. SOC.,Perkin Tram. I 1981,2415. (b) Sato, F.; Uchiyama, H.; Iida, K.; Kobayashi, Y.; Sato, M. J. Chem. SOC.,Chem. Commun.1983,921. (c) Chou, T. S.; Tos, H. H.; Tao, Y. T.; Lin, L. C. J. Org. Chem. 1987,52, 244. (d) Cages, B.; Colovray, V.; Cove, J. Tetrahedron Lett. 1988,29,627. (10) (a) Mildland, M. M.; Lee, P. E. J. Org. Chem. 1981,46,3933. (b) Miyachi, N.; Shibaeaki, M. J. Org. Chem. 1990,55,1975. (c) Sha,C. K.; Jean, T.S.; Wang, D. C. Tetrahedron Lett. 1990,31,3745. (d) Wu, G . Z.;Cederbaum, F. E.; Negishi, E. I. Tetrahedron Lett. 1990,31,493. (e) Soderquist, J. A.; Gisela, L. C. Tetrahedron Lett. 1991,32,43. (f)Feldman, K. S.; Bums,C. J. J. Org. Chem. 1991,56,4601. (9) Nishikawa, T.; Ino,A.; Isobe, M.; Goto, T. Chem. Lett. 1991,1271. (11) (a) Jones,T. K.; Denmark, S. E. Org. Synth. 1986,64, 182. (b) Miller, R. B. Synth. Commun. 1972,2, 267. (12) (a) Corey, E. J.; Ruden, R. A. Tetrahedron Lett. 1973,1495. (b) Shen, Y. C.; Liao, Q.M. J. Organomet. Chem. 1988,346, 181.
R2
RLi BuLi p-ClC6Hd H BuLi p-ClCBH4 H t-BuLi p-ClCBH4 H MeLi p-CICsH4 H PhLi p-BrC6H4 H BuLi P-FCeHd H BuLi p-MeC6H4 H BuLi 2-pyridyl H BuLi 2-naphthyl H BuLi cyclohexyl H BuLi C6H5 CH3 BuLi -(CH&BuLi -(CH2)&H=CHBuLi
product
H
28 2b
yield (%). 76 87
2b 2b
85
2b
2c 2d 2e
2f 2g 2h 2i 2j
2k
71 72 84
88 93 91 90 67 79 80 82
Isolated yield baaed on carbonyl compound.
-
R'F?CCH2C=CSiMe3
R'
C6H5
The preparation of compounds 2 has been performed on a variety of structurally different carbonyl compounds to determine the scope of the reaction. Some experimental results are summarized in Table I and illustrate the efficiency, the applicability, and the scope of the present method. As shown in Table I, the reaction is of wide scope and works well with both enolizable and nonenolizable carbonyl compounds. As for 8-monosubstituted a,@enones, only a 1,2-addition product was isolated and no 1,4-adduct was detected (entry 14). The importance of the propargylic anions in synthetic chemistry emerged from the recognition of thek utility for the extension of the carbon chain and the facility in the interconversion of the functi~nality.'~Their applicability in organic synthesis, however, has been limited because of the difficulties in controlling the regio- and stereoselectivities of the reaction. It is often pointed out that the propargylic anion may be in equilibrium with the allenic Thus, in the condensation with carbonyl compounds, two products-acetylenic and allenic alcoholscan be formed. Recently, considerable attention has been paid to the control of the propargyl-allenic equilibrium for practical synthetic purposes. In the specific case of the trimethylsilyl derivatives 3 and 4 (eq 2, M = metal) the Me,Si
\
M'
C=C =CH2
= Me,SiC Z C C H 2 M
(2)
4
3
lithium reagent (M= Li) is particularly effective in adding to alkyl and allyl halides,ls as well as to epoxides,17with regiocontrolled formation of propargylic products. However, in condensation with aldehydes it gave both allenic and acetylenic adducts as major producte.ls The derived cuprate (M = Cu) is recognized to enter into conjugate addition with s i m i i results.lg The Grignard reagent (M = MgX) also reacts in the propargylic form but adds to (13) (a) Maercker, A. Org. React. 1965,14, 270. (b) Johnson, A. W.; Martin, J. 0. Chem. Ind. (London) 1965,1726. (c) Huang, Y. Z.;Shen, Y. C. Adu. Organomet. Chem. 1982,20,115-157. (14) For relative reviews, see: (a) The Chemistry of the CarbonCarbon Triple Bond; Patai, S., Ed.; Wiley: New York, 1978. (b) The Chemistry of Ketenes, Allenes, and Related Compounde; Patai, S., Ed.; Wiley: New York, 1980. (c) Brandma, L.; Verkruijsee, H. D. Synthesis of Acetylenes, Allenes and Cumulenes; Elsevier; Amsterdam, 1981. (15) Suzuki, M.; Morita, Y.;Noyori, R. J. Org. Chem. 1990,55,441. (16) Corey, E. J.; Kirst, H. A. Tetrahedron Lett. 1968, 5041. (17) Stork, G.; Kowalski, C.; Garcia, G. J. Am. Chem. SOC.1976,97, 3258. (18) Corey, E. J.; Rucker, C. Tetrahedron Lett. 1982,23,719 (see the fifth line from the bottom on p 721). (19) Han, Y.-K.; Paquette, L. A. J. Org. Chem. 1979,44,3731.
Zhou et al.
6600 J. Org. Chem., Vol. 67, No.24,1992
Scheme I I
I
R
Li
I
R
CH2= C =CSiMe,
I
+ i-B&TeBr
i. R ‘ R ~ C O ii. H#
OH
I
R’R2CCH2CfCSiMe3 2
7
6
i-Bu2Te---CH2=C
-
]
LiEr -Eu~T$R
Er-
[-
R‘R2CCH2C3XiMe,
5’
aldehydes and ketones only in low yield.20 The reactions of titanium21and aluminum derivative@ (M = Ti, Al) with aldehydes both gave allenic adducts. Although the zinc derivative (M = Zn) reacts with carbonyl compounds in propargylic form, the yield is still limited.22 Thus, this RLi-promoted, highly regioselective condensation of the telluronium salt 1 with carbonyl compounds is a novel alternative method for the synthesis of (trimethylsily1)propargyl alcohols. It is noteworthy that, in the absence of RLi, the reaction did not take place at all under the same reaction conditions. Various alkyl- and aryllithium reagents such as n-BuLi, t-BuLi, MeLi, and PhLi could promote the reaction effectively (Table I). Instead of formation of a silylatad telluronium ylide, as in the case of phosphonium or arsonium analogs,12an unstable tetraorganyltelluriumintermediate (6) may be formed, as in the case of Bu3TeLa3 In the presence of LiBr, a lithium-tellurium exchange reaction, similar to that of diorganyl telluride, may take place.24 The in situ generated lithium species 6 reacted with carbonyl compoundsto give (trimethylsiiy1)propargyl alcohols 2 as shown in Scheme I (path A). Another possibility (path B) has also been considered for this RLimediated reaction. The intermediate 5 may be polarized as in 5’ in the presence of Li+ owing to the weakness of the Te-C bond. The anion formed from the cleavage of the tellurium-carbon bond of intermediate 5’ could then attack the carbonyl compound to form intermediate 8. Reaction of 8 with LiBr could lead to the stable telluronium salt 7 and intermediate 9, and hydrolysis of 9 would give rise to 2. It is noteworthy that, in the PhLi-promoted reaction of the telluronium salt 1 with p-chlorobenzaldehyde,we did isolate the byproduct 7 as a colorless crystal before hydrolysis, viz. phenyldiisobutyltelluronium bromide, which gave satisfactory elemental analysis, ‘HNMR,FAB-MS. It is of interest that the lithium-tellurium exchange reactions could be avoided effectively by the use of a nonnucleophilic base, such as LDA, instead of the nu(20) Komarov, N.V.;Shostakoskii, M. F.; AeWeva, L. N.Zh. Obshch.
Khim. 1961,31,2100. (21) Iehiguro, M.; Ikeda, N.; Yamamoto, H. J. Org. Chem. 1982,47,
2227. (22) Daniek, R. G.;Paquette, L. A. Tetrahedron Lett. 1981,22,1579. (23) Hellwinkle, D.; Farbach, G.Chem. Ber. 1968,101,574. (24) (a) Hiiro,T.; Kambe, N.;Ogawa, A.; Miyoehi, N.;Murni, S.; Sonoda, N. Angew. Chem., Znt. Ed. Engl. 1987,26,1187. (b) Hiiro, T.; Mogami, T.; Kambe,N.;Fujiwara, 5.I.; Sonoda, N. Synth. Commun. 1990,20,703. (c) Hiiro, T.; Morita, Y.;Inoue, T.; Kambe, N.;Ogawa, A.; Ryu, I.; Sonoda, N.J. Am. Chem. Soc. 1990, 112,465 and references cited therein. (d) Reich, H.J.; Green,0. P.; Philips, N.H. J. Am. Chem. SOC. 1991,113,1414. (25) The actual reactive specie0 would probably be free lithium reagent 6 or p o l a r i i lithium reagent 6’ rather than tetraorganyltellurium intermediate I, because only 1,2-addition to 2-cyclohexen-1-oneoccurred in the present system, quite similar to that in a (CH2C-C-Tl€’S)Li/F system.18 Furthermore, the reaction works well wth acetophenone, whch also indicates that the reactive species may be 8’ and/or 6.
9
]H#
2
Scheme I1 ia&Te+CH2CZCSiMe,
Br-
LiTMPflHF
-78 r:
I
R,’
,c-c,!\
,C3XiMe3
+
/o\
/H
R2,“-cbC
H ’ 11 (cis, major)
R2
R’\
ECSiMe, 11’ (trans, minor)
Table 11. Highly Stereomelective Synthesis of cis -(Trimethylsilyl)alkynyl Epoxides 11
total R’
entry 2 3 4 5 6 7 8 9 IO 11
PCIC6H4 p-BrC6Hd 2-naphthyl 4-PhC6H4 cyclohexyl n-C,HB n-CsH11 n-CgH,g CsH5
R* H H H H H H H H H CH,
product 11 1la
yield cis/transo 8218 982 982 81:19 m12 99:1 982 982 923 86A4
llb 1I C 1 Id 1 le
11f
w4
(%)b
76
80 80 96 96
86 83
llh 82 1 li 94 llj 96 80 C6H5 Ilk ODetermined by 200-MHz ‘H NMR and/or NOE. bIsolated yields based on carbonyl compounds.
cleophilic organolithium reagent. The telluronium salt 1, after being treated with LDA in THF at -78 O C under N2, reacted with p-chlorobenzaldehyde to give cis-3-(4chloropheny1)-2-[(trimethylsily1)ethynylJoxiranein 66% yield (eq 3). To our surprise, the result is different from that of the reactions of carbonyl compounds with the corresponding phosphonium and arsonium ylides.l2 i-B&Te+CH&SCSiMe,
Br-
1. LDAlTHF
2. pCIC&l&HO
-78 ’c
-78%
-+ r 1
-
1
0
/-\
pCiCeH,-C-C,-CECSiMe3 H‘ H
+ i-Bu2Te (3)
This significant result prompted us to explore more effective bases for the generation of the silylated telluronium ylide. We found that lithium 2,2,6,6-tetramethylpiperidide,= which is less nucleophilic and more basic than (26) Upton, C. J.; Beak, P. J. Org. Chem. 1976,46, 1094.
Reactions of Carbonyl with Telluronium Bromide
J. O g . Chem., Vol. 57, No.24, 1992 6601
Scheme 111
Scheme V" 0-TeR,
C , ECSiMe,
R""4C
W NOE
p;clha
GCSiMe,
-O R'd 4C
Te+b =CSiMe,
(trans-oxatelluretane)
A
111 (Jj.2 = 4 Hz)
R'
Scheme N C6 H5
0 CECSiMe, \ / \ / ,c-C C"$ H '
W NOE l l j (cis)
C6H5,
/o\ H,
,c-C CHI
O-TeR2
paha
-O
-
Te+R2
__L
no NOE
R'
R'uC
ZXiiMe,
(cis-oxatelluretane)
1 l j ' (trans)
(27) Recent efforta for the preparation of disubstituted osiranes: (a) Still, W. C.; Novack, V. J. J. Am. Chem. SOC.1981,103,1283. (b) Yamaguchi, M.; Mukaiyama, T. Chem. Lett. 1982, 237. (c) Auge, J.; David, S. Tetrahedron Lett. 1983,24,4009. (d) Ousset, J. B.; Mioakowski, C.; Solladie, G. Tetrahedron Lett. 1983,24,4419. (e) Furuta, K.; Ikeda, Y.; Mequriya, N.; Ikeda, N.; Yamamoto, H. Bull. Chem. SOC.Jpn. 1984,57, 2781. (28) Hsi, H. D.; Koreeda, M. J . Org. Chem. 1989,54, 3229. (29) Maryanoff, B. E.; Reitz, A. B.; Mutter, M. S.;Inners, R. R.; Almond, H. R., Jr.; Whittle, R. R.; Olofson, R. A. J. Am. Chem. SOC.1986, 108,7664. ~~
(cis epoxide)
'CZCSiMe,
LDA, is more suitable for generating the silylated telluronium ylide 10. Ylide 10 reacted with carbonyl compounds to afford (trimethylsily1)alkynyl epoxides 11 in good yields with high cis stereoselectivity (Scheme 11). The results are shown in Table 11. As shown in Table 11, we can see that this new method for the direct propargyl transfer to carbonyl compounds is of wide scope and occurs with high cis sterewelectivity. The reaction works well with both enolizable and nonenolizable carbonyl compounds, including aromatic aldehydes, aliphatic aldehydes, and ketones. The cis-oxirane was generally characterized by a coupling constant between the vicinal oxirane hydrogens of about 4 Hz observed in the 'H NMR spectrum.n On the other hand, the trunsoxirane was characterized by a coupling constant of about 2 H z . ~To support this conclusion,we measured the NO% of oxirane lli as shown in Scheme 111. For irradiation of 1-H, the NOE of 2-H is 8.20; while when 2-H was irradiated, the NOE of 1-H is 10.00. The configurations of oxiranes l l j and l l j ' were determined by the NOE technique as shown in Scheme IV. For isomer 11j: irradiation of 2-H resulted in an NOE of 5.72 for the methyl protons. When the methyl hydrogens were irradiated, the NOE of 2-H was 5.80, thus isomer l l j must be cis. On the other hand, no NOE was observed for isomer 11j', so the configuration of 11j' would be trans. The mechanism illustrated in Scheme V would account for our results described above. We presume that the reaction proceeds via oxatelluretane similar to that of arsonium ylidetxU It might be anticipated that cis-oxatelluretane is destabilized relative to trans-oxatelluretane due to the steric interaction between the (trimethylsily1)ethynyl and R' groups. trans-Oxatelluretane opens to the corresponding betaine through catalysis by the lithium salt present under the reaction conditions,29which collapses to the cis epoxide product (pathway a). The cis-oxatelluretanein the presence of lithium salt can open to the correspondingbetaine, which subsequently collapses to trans epoxide products (pathway b). Apparently, the high cis stereoselectivity observed for the epoxide forma-
~
CZCSiMe,
A
R'
CECSie,
(trans epoxide)
"R = i-Bu2
tion suggests that process a is highly favored over process b. cis-(Trimethylsily1)akynyl epoxidea reported herein are expected to be useful in organic synthesis due to their novel structure and several functional groups. The epoxides can be reduced to cis terminal enynes,30which have attracted much attention due to their biological proper tie^.^^ Furthermore, the epoxide ring can also be opened regiospecifidy by nucleophilic reagent to yield potentially useful 8-substituted In summary, a novel method for direct synthesis of cis trimethylsilylalkynyl epoxides from carbonyl compounds has been described by the use of the silylated semistabilized telluronium ylide. However, the telluronium salt 1, after being treated with alkyl- or aryllithium reagent, reacted with carbonyl compounds to give (trimethylsily1)propargyl alcohols in high yields with high regioselectivity. It is expected that the abovedescribedreaction will find considerable application to the synthesis of acyclic molecules having adjacent chiral centers. Further work in this area is now in progress in our laboratory. Experimental Section All reactions were carried out under N2. THF was distilled from sodium and benzophenone under Nz. The NOES were measured at 400 MHz. MS data were obtained with electron ionization. Diisobutyl telluride%and LiTMP%were prepared according to the reported methods. Synthesis of [3-(Trimethylsilyl)-2-propynyl]dii~obutyltelluronium Bromide (1). Diisobutyl telluride (50 "01) was under Nz syringed into 3-bromo-l-(trimethylsilyl)-l-propyne without solvent. The mixture was stirred for 4 h at rt to afford ~~
~
~~
(30) (a) Sarmah, P.; Barua, N. C. Tetrahedron Lett. 1988,29, 5815. (b) Mandel, A. K.; Mahajan, S. W. Tetrahedron 1988,44,2293. (c) Wong, H. N. C.; Fork, C. C. M.; Wong, T.Heterocycles 1987, 26, 1345. (d) Yanada, K.; Yanada, R.; Meguri, H. Chem. Pharm. Bull. 1989,37,3423. (e) Mitani, M.; Mataumoto, H.; Gouda, N.; Koyama, K. J. Am. Chem. SOC.1990,112,1286. (f) Schobert, R.; Hohlein, W. SynLett 1990,465. (31) (a) Fujimoto, R.; Kiehi, Y.; Blount, J. F. J. Am. Chem. SOC.1980, 102,7154. (b) Sakemi, S.; Totton, L. E.; Sun,H. H. J. Nat. Prod. 1990, 53, 995. (c) Guella, G.; Pietra, F. m u . Chim. Acta 1991, 74, 47. (32) (a) Saito, S.;Niehikawa, T.; Yokoyama, Y.; Moriwake, J. N. Tetrahedron Lett. 1990,31,221. (b) Iqbal, J.; Pandey, A. Tetrahedron Lett. 1990,31,575. (c) Chakraborty, T. K.; Reddy, G. V. Tetrahedron Lett. 1990,31, 1335. (33) Balfe, M. P.; Chaplin, C. A.; Philips, H. J. Chem. SOC.1938,341.
Zhou et al.
6602 J. Org. Chem., Vol. 57, No.24, 1992 a white crystal. mp 102-104 "C;'H NMR (90 MHz, CDClJ 6 3.58 (8, 2 H), 3.00 (d, J = 7 Hz, 4 H), 2.30 (m, 2 H), 2.04 (d, J = 7.2 Hz, 6 H), 2.02 (d, J = 7.2 Hz, 6 H), 0.10 (s,9 H); FAB-MS, m/e (re1 intensity) 355 (C+,' q e , loo), 353 (C+, ' T e , 93), 351 (C', '28Te, 58), 298 (i-BuTe+CHzMSiMe3,' q e , l),296 ( ' q e , 11, 294 ( ' V e , l),244 (i-Bu2Te+,' q e , 4), 242 ('28Te, 4), 240 ('28Te, 3), 187 (i-BuTe+, l q e , 3), 185 (128Te, 3), 183 ( ' w e , 3), 111 (CH2WSiMe3+,3), 57 (281,789 ([M + C]+,' q e , 0.8),787 ('28Te, l.O), 785 ( ' q e , 0.6); IR (KCl) 2950 (s), 2150 (s), 1380 (s), 1360 (8) cm-'. Anal. Calcd for C14H&rSiTe: C, 38.84; H,6.75; Br, 18.45. Found: C, 38.50; H, 6.77; Br, 18.52. Highly Redoeelective Synthesis of (Trimethylsily1)propargyl Alcohols 2. The synthesis of 1-(4-chlorophenyl)-4trimethy1-3-butyn-l-o1(2b) is a typical procedure. A solution of BuLi (0.6 mL, 1.5 mmol) in hexane was syringed into a solution of the telluronium salt 1 (0.65 g, 1.5 mmol) in dry THF (10 mL) at -78 "C under Nz. After 30 min, a solution of p-chlorobenzin THF (2 mL) was added dropwise aldehyde (168.6 mg, 1.2 "01) at -78 "C, and the reaction mixture was allowed to warm to rt. After the reaction was complete (monitored by TLC), 1 mL of HzO was added to the mixture, and the solution was stirred for another 1h. The mixture was then extracted with ether (5 mL x 3). The combined organic extracts were washed with brine, dried over Na2S04,filtered, and concentrated under reduced pressure. After flash chromatography on a silica gel column, 1-(4-chlorophenyl)-4-(trimethylsilyl)-3-butyn-l-ol (2b,265 me) was obtained in 87% yield (GC shows >98% purity). l-Pheny1-4-(trimethylellul)-3-butyn-l-o1(2a):200 mg, 76%; pale yellow liquid;M'H NMR (90 MHz, CDC13) 6 7.13 (s,5 H), 4.60 (t,J = 6 Hz, 1H), 3.05 (br 8, OH),2.42 (d, J 6 Hz, 2 HI, 0.03 (8, 9 H); EIMS m/z (re1 intensity) 200 (M+ - HzO, 31, 185 (8), 179 (18),107 (M+ - CHzC& SiMe3, NO), 85 (27), 73 (20); 2980 (m), 2200 (m) cm-'. IR (neat) 3450 (w), l-(4-Chlorophenyl)-4-(trimethylsilyl)-3-butyn-l-ol (2b): 265 mg, 87% (BuLi); 215 mg,71% (t-BuLi); 258 mg, 85% (MeLi); 218 mg, 71% (PhLi); colorless liquid 'H NMR (90 MHz, CDClJ 6 7.17 (s,4 H), 4.62 (t,J = 7 Hz, 1 2.89 (br 8, OH), 2.44 (d, J = 7 Hz, 2 H), 0.06 (s,9 H);EIMS m/z (re1 intensity) 235 (M+ -OH, 2), 213 (16), 141 (85), 112 (21),97 (lo), 73 (100);IR (neat) 3400 (w), 2980 (m), 2190 (m) cm-'. Anal. Calcd for C13H1+210SI: C, 61.76; H, 6.78; C1,14.02. Found: C, 62.01; H, 6.90; C1,13.72. 1-(4-Bromophenyl)-4-(trimethylsilyl)-3-butyn-lol(2c):303 mg, 85%; colorless liquid; 'H NMR (90 MHz, CDClJ 6 7.11 (m, 4 H), 4.47 (t,J = 6 Hz, 1H), 3.58 (br 8, OH), 2.35 (d, J = 6 Hz, 2 H), 0.0 (s,9 H); EIMS m/e (re1 intensity) 281 (M+- OH, 81Br, l),279 (M+-OH, q r , l),265 (3), 263 (3), 259 (20), 257 (21), 187 2950 (24), 185 (loo), 159 (9), 157 (lo), 73 (87); IR (neat) 3350 (w), (m), 2180 (w) cm-'. Anal. Calcd for C13H17BrOSi:C, 52.53; H, 5.76; Br, 26.88. Found: C, 52.22; H, 5.78; Br, 26.88. 1-(4-Fluorophenyl)-4-(trimethylsilyl)-3-butyn-l-ol (2d): 250 mg, 88%; pale yellow liuqid; 'H N M R (90 MHz, CDClJ 6 7.34 (m, 4 H), 4.94 (t,J = 6 Hz, 1 H),2.74 (d, J = 6 Hz, 2 H), 2.64 (br 8, OH), 0.24 (s, 9 H); EIMS m/z (re1 intensity) 235 (M+ - 1, l),218 (M+- OH2, l),197 (21), 125 (M+ - CH#2SiMe3, 1001, 112 (18), 97 (45), 73 (99); IR (neat) 3400 (w), 2980 (s), 2200 ( 8 ) cm-'. Anal. Calcd for C13H17FOSi: C, 66.06; H, 7.25. Found C, 65.56; H, 7.32. 1-(4-Methylphenyl)-4-(trimethylsilyl)-3-butyn-l-ol(2e): 260 mg, 93%; pale yellow liquid; 'H N M R (90 MHz, CDClJ 6 7.17 (a, 4 H), 4.77 (t,J = 6 Hz, 2 H), 2.59 (d, J = 6 Hz, 2 H), 2.44 (br 8, OH), 2.29 (e, 3 H), 0.13 (e, 9 H); EIMS m/z (re1 intensity) 231 (M+ - 1,l),214 (M+- OH,, l),193 (B), 121 (M+ - CHzCdSiM%, loo), 105 (lo), 93 (24), 73 (51); IR (neat) 3450 (w), 2950 (m), 2180 (m) cm-'. Anal. Calcd for C14HmOSi:C, 72.36; H, 8.67; Found C, 71.98; H, 8.69. 1-(2-Pyridyl)-4-(t1h&hyl~ily1)-3-b~t~-l-01(2f): 240 mg, 91%; pale yellow liquid; 'H NMR (60 MHz, CDC13) 6 8.30 (m, 1 H), 7.40 (m, 3 H), 4.65 (t,J = 6 Hz, 1H), 4.60 (br 8, OH), 2.53 (d, J = 6 Hz, 2 H), 0.03 (8, 9 H); EIMS m/z (re1 intensity) 220 (M+ + 1, loo), 218 (M+ - 1,20), 204 (20), 166 (15), 108 (M+ CHzC4SiMe3, 19), 73 (6); IR (neat) 3300 (vs), 2950 (m), 2150 (m) cm-'.Anal. Calcd for ClZHl7NOSi:C, 65.71; H, 7.81; N, 6.39. Found: C, 65.65; H, 7.80; N, 6.37.
l-(2-Naphthyl)-4-(trimethylsilyl)-3-butyn-l-ol (2g): 290 mg, 90%; colorless liquid; 'H NMR (60 MHz, CDClJ 6 7.80 (m, 4 H), 7.50 (m, 3 H), 5.02 (t, J = 6 Hz, 1 H), 2.86 (d, J = 6 Hz, 2 H), 2.50 (br s, OH), 0.13 (e, 9 H); EIMS m/z (re1intensity) 268 (M+, 2), 267 (M+ - 1, l),251 (M+ - OH, 61), 229 (13), 157 (M+ - CHZMSiMe3,loo), 129 (76), 73 (95);IR (neat) 3350 (w), 3010 (m), 2950 (m), 2180 (m) cm-'.Anal. Calcd for C17HmOSi.C, 76.07, H, 7.51. Found C, 75.77; H, 7.53. l-Cy~l0he~yl-4-(trimethyl~ilyl)-3-b~tm1-01(2h): 180 mg, 67% colorless liquid;u 'H NMR (60 MHz, CDC13) 6 4.00 (m, 1 H), 2.43 (br s, 1 H, OH), 2.40 (d, J = 6 Hz, 2 H), 1.10-2.10 (m, 11H), 0.15 (e, 9 H); EIMS m/z (re1 intensity) 224 (M+,31,207 (M+- OH, 46), 185 (73), 147 (98), 133 (81), 95 (loo),73 (66); IR (neat) 3400 (vs), 2900 (s), 2850 (m), 2150 (m) cm-'. l-Methyl-l-phenyl-4-(trimethylsilyl)-3-butyn-1-01(2i): 210 mg,79%; colorless liquid;= 'H NMR (60 MHz, CDClJ 6 7.25 (m, 5 H), 2.50 (br 8, 1H, OH), 2.42 (8, 2 H), 1.45 (8, 3 H), 0.03 (e, 9 H); IR (neat) 3350 (vs), 2090 (s), 2180 ( 8 ) cm-'. 1-[ ( T r i m e t h y l ~ i l ~ l ) p ~ ~ 1 ] ~ ~ ~ 1 0 h e ~ a 1 1 -202 1 - mg, 01(2j): 80%; colorless liquid;n 'H NMR (60 MHz, CDC13) 6 2.45 (s, 2 H), 1.72-3.15 (m, 10 H), 1.70 (br s, 1H, OH), 0.10 (s,9 H); IR (neat) 3350 (vs), 2950 (81, 2150 (81, 1250 (81, 840 (e) cm-'. 1-[ (Trimethylsilyl)propargyl]-2-cyclohexen-l-o1(2k):205 mg,82%; pale yellow liquid; 'H NMR (60 MHz, CDC13) 6 6.0 (m, 2 H), 2.40 (s,2 H), 1.75-3.15 (m, 6 H), 1.70 (br 8, 1H,OH), 0.12 (s,9 H); EIMS m/z (re1 intensity) 217 (M+ 1,0.14), 191 (M+ - OH, 26),97 (M+- CH2C=CSiMe3,loo), 73 (SiMe3'+, 19); IR 2950 (s), 2140 (e), 1250 (e), 840 (8) cm-'. (neat) 3400 (w), PhenyldiisobutyltelluroniumBromide (7,R = Ph). This compound was prepared by a similar procedure to the synthesis in ether of 2b using PhLi. A solution of PhLi (0.6 mL, 0.6 "01) was syringed into a solution of the telluronium salt 1 (0.26 g, 0.6 mmol) in dry THF (5 mL) at -78 "C under NP After 30 min, a solution of p-chlorobenzaldehyde (70 mg, 0.5 mmol) in THF (1mL) was added dropwise at -78 OC. The reaction mixture was allowed to warm to rt and stirred for another 2 h. THF was removed in vacuo and petroleum ether/ethyl acetate (91,lO mL) was added. The white solid appeared in the bottom of the reaction tube. After filtration and washing of the residue with ether, phenyldiiiobutyltelluronium bromide (7) (190mg) was obtained in 79% yield mp 136138 "C; 'H NMR (90 MHz, CDClJ 6 7.60 (m, 5 H), 3.80 (dd, J1 = 11 Hz, J2 = 7 Hz, 2 H), 3.24 (dd, J1= 11Hz, J2 = 7 Hz, 2 H), 2.30 (m, 2 H), 1.14 (d, J = 7 Hz, 6 H), 1.02 (d, J = 7 Hz,6 H); FAB-MS m z (re1intensity) 321 (C+,' q e , 100),319 (C+,' q e , 931,317 (C+, e, 59), 264 (i-BuTe+Ph,' q e , 3), 262 ( ' q e , 3), 260 ( ' q e , 3), 187 (i-BuTe+,' q e , 4), 185 ( ' q e , 4), 183 ( ' q e , 2), 721 ([M C]+, ' q e , l), 719 ( q e , 2), 717 ( q e , 1); IR (KBr) 3010 (m), 1570 (m), 1425 (m), 1380 (m), 1360 (s), 745 (s), 682 ( 8 ) cm-'. Anal. Calcd for C1,HmBrTe: C, 42.16; H, 5.81; Br, 20.03. Found C, 41.92; H,5.70; Br, 20.42. Highly Stereoselective Synthesis of (Trimethylsily1)ethynyl Epoxides 11. Typical procedure for the synthesis of 3-phenyl-2-[(trimethylsilyl)ethynyl]osirane (1 la). A solution of LiTMP (2 mL, 1.2 mmol) in THF was syringed into a solution of the telluronium salt 1 (0.53 g, 1.2 mmol) in dry THF (8 mL) at -78 "C under NP The solution turned red. After 30 min, a in THF (2 mL) was solution of benzaldehyde (106 mg,1.0 "01) added dropwise at -78 "C, and the reaction mixture was allowed to warm to rt. After the reaction was completed (monitored by TLC), 1mL of HzOwas added to the mixture and it was stirred for 30 min more. The mixture was then extracted with ether (5 mL x 3). The combined organic extracts were washed with brine, dried over NaZSO4,filtered, and concentrated in vacuo. After column chromatography on silica gel (eluting with petroleum ether and 2% triethylamine) gave the desired 3-phenyl-2-[(trimethylsilyl)ethynyl]oxirane (118 and lla') (165 mg) in 76% yield (GC shows >98% purity). 3-Phenyl-2-[(trimethylsilyl)ethl]o~e: 165 mg, 76%; Ila (cis isomer) pale yellow liquid 'H N M R (200 MHz, (CDJ&O) 6 7.35 (m, 5H), 4.16 (d, J = 4 Hz, 1H), 3.77 (d, J = 4&, 1H), 0.02 (s,9 H); 1 la' (trans isomer) pale yellow liquid 'H NMR (200 MHz, (CD3)&!O) 6 7.17 (m, 5 H), 3.88 (d, J = 2 Hz, 1 H), 3.33 (d, J = 2 Hz,1 H), 0.02 (a, 9 H); mixture of lla and 118' EIMS
(34) Furuta, K.;Ishiguro, M.; Haruta,R.; Ikeda, N.; Ya"ot0, Bull. Chem. SOC.Jpn. 1984,57,2368.
(35) Eiter, K.; Lieb,F.;Dhlnkotter, Chem. 1978,658.
k),
H.
-
4
+
H.;Oediger, H.Liebigs Ann.
Reactions of Carbonyl with Telluronium Bromide
m/z (re1 intensity) 216 (M+, lo), 201 (171,185 (lo), 141 (22), 73 (SiMe3*+,100); IR (neat) 2960 (m), 2160 (m), 1250 (s), 1060 (e), 760 ( 8 ) cm-'; HRMS m/z calcd for C13H160Si216.0971, found 216.0990. 3-(4-Chlorophenyl)-2-[(trimethylsilyl)ethynyl]osirane (Ilb): 200 mg,80%;pale yellow liquid; 'H N M R (60 MHz, CClJ 6 7.20 (8, 4 H), 3.90 (d, J = 4 Hz, 1H), 3.50 (d, J = 4 Hz, 1H), 0.03 ( ~ , H); 9 '9C NMR (90MHz, (CDJ,CO/TMS) 6 135.0,130.1, 129.0, 101.4, 92.8, 59.2, 49.1,O.R EIMS m/z (re1 intensity) 325 (M+ SiMe,, "Cl, 52), 323 (M++ SiMe3,Wl,1001,252 (M+,"C1, 29), 250 (M+, 35C1,66), 235 (47), 215 (33), 141 (23), 73 (60); IR (neat) 2960 (m), 2150 (m), 1250 (a), 840 (s), 760 (e) cm-'; HRMS m / z calcd for C13H15 W O S i 250.0581, found 250.0580; calcd for C13H1537C10Si252.0551, found 252.0525. 3-(rl-Bromophenyl)-P-[(trimet hylsily1)et hynylloxirane (11~):236 mg,80%;pale yellow liquid; 'H NMR (200MHz, C&,J 6 7.28 (d, J = 8 Hz, 2 H), 7.02 (d, J = 8 Hz, 2 H), 3.41 (d, J = 4 Hz, 1H), 3.28 (d, J = 4 Hz, 1H), 0.09 (s,9 H); EIMS m/z (re1 intensity) 296 (M+,61Br,17), 294 (M+, %r, 15), 281 (15), 279 (13), 215 (15), 187 (19), 185 (15), 141 (23), 110 (28),95 (66),73 (SiMe;', 100); IR (neat) 2950 (m), 2150 (m), 1250 (s),&U) (w), 770 (8) cm-'; HRMS m/z calcd for Cl3H129BrOSi 294.0076, found 294.0099; calcd for Cl3H1?'BrOSi 296.0174, found 296.0154. 3-(2-Naphthy1)-24(trimet hylsilyl)ethynyl]oxirane ( 1 1d): 253 mg, 95%; l l d (cis isomer) pale yellow liquid 'H NMR (200 MHz, CsD6) 6 7.3-7.8 (m, 7 H), 3.87 (d, J = 4 Hz, 1H), 3.56 (d, J = 4 Hz,1H), 0.15 (s,9 H); lld' (trans isomer) 'H NMR (200 MHz, C6De)6 7.15-7.55 (m, 7 H), 4.06 (d, J = 2 Hz, 1H), 3.21 (d, J = 2 Hz,1 H), 0.20 (s,9 H); EIMS m/z (re1 intensity) 267 (M+ 1,8), 266 (M+, 35), 251 (22), 237 (64), 223 (23), 209 (25), 127 (22), 95 (26), 73 (SiMe3*+,100); IR (neat) 3050 (m), 2150 (m), 1250 (81,845 (-1,810 ( 8 ) cm-'; HRMS m/z calcd for Cl7Hl8OSi 266.1130, found 266.1120. 3-(4-Biphenylyl)-2-[(trimethylsilyl)ethynyl]olirane(1le): 297 mg,95%; lle (cis isomer) mp 68-70 OC; 'H NMR (200 MHz, CD3COCD3)6 7.71 (m, 4 H), 7.50 (m, 5 H), 4.28 (d, J = 4 Hz, 1 H), 3.87 (d, J = 4 Hz, 1 H), 0.08 (s,9 H); lle' (trans isomer) mp 70-72 OC; 'H NMR (200 MHz, CD3COCD3)6 7.70 (m, 4 H), 7.51 (m, 5 H), 4.14 (d, J = 2 Hz, 1 H), 3.60 (d, J = 2 Hz, 1H), 0.20 + 1,16), 292 (M+,58), (s,9 H); EIMS m/z (re1intensity) 293 (M+ 277 (26), 249 (20), 235 (23), 181 (141,165 (37), 152 (16), 95 (29), 73 (SiMe3*+,100); IR (KCl) 2950 (s), 2150 (m), 1250 (s), 860 (m), 770 ( 8 ) cm-'; HRMS m/z calcd for Cl&ImOSi 292.1283, found 292.1290. 3 - C y ~ l o h e . r 1 - 2 - [ ( t ~ e t h y l ~ ~ l ~ (110: ~ y l ]190 0~e mg,86%;colorlegs liquid; 'H N M R (200 MHz, CD3COCD3) 6 3.42 (d, J = 4 Hz,1H), 2.76 (dd, J1= 8 Hz, J2= 4 Hz, 1 H), 1.75 (m,
+
+
J. Org. Chem., Vol. 57, No. 24, I992 6603 5 H), 1.25 (m, 6 H), 0.12 (s,9 H); EIMS m/z (re1 intensity) 295 (M+ + &Me3, 29), 223 (M+ 1,32), 222 (M+, ll),207 (30), 183 (58), 133 (99), 95 (66),81 (loo), 73 (60); IR (neat) 2800 (81,2150 (m), 1250 (s), 845 (vs), 760 (m) cm-'; HRMS m/z calcd for C13HlzOSi 222.1526, found 222.1525. Anal. Calcd for C13HnOSi: C, 70.21; H, 9.97. Found C, 70.31; H, 9.85. 3-Butyl-2-[(trimethylsilyl)ethyl]oxirane (1lg): 163 mg, 83%; colorless liquid; 'H NMR (200 MHz, C&) 6 3.19 (d, J 4 Hz, 1 H), 2.64 (m, 1 H),1.70 (m, 2 HI, 1.30 (m, 4 H), 0.12 (8, 9 H); EIMS m/z (re1 intensity) 197 (M+ + 1,9), 196 (M+,7), 195 (M+- 1,9), 181(50),110 (42),95 (70),73 @Me3'+, 100);IR (neat) 2950 (81, 2150 (m), 1250 (81, 845 (81, 760 (e) cm-'; HRMS calcd for CllHzoOSi 196.1284, found 196.1280. 3 - P e n t y l - 2 - [ ( t r i m e t ~ l s ~ l ~ t ~ y l(llh): ] o r i 172 mg, 82%; colorless liquid; 'H NMR (200MHz, CD3COCD3)6 3.44 (d, J = 4 Hz,1H), 3.04 (m, 1H), 1.3-1.6 (m, 8 H), 0.92 (t,J = 8 Hz, 3 H), 0.20 (s,9 H); EIMS m/z (re1intensity) 211 (M+ + 1,2), 209 (M+ - 1, 2), 195 (22), 183 (18), 147 (16), 110 (28), 75 (23), 73 (SiMe3'+, 100); IR (neat) 2950 (s), 2150 (m), 1250 (s), 845 (81,760 ( 8 ) cm-'. Anal. Calcd for Cl2HnOSi: C, 68.51; H, 10.54. Found C, 68.49; H, 10.52. 3-Nonyl-2-[(trimethylsilyl)ethynyl]oxirane(lli): 205 mg, 94%;colorless liquid; 'H NMR (200MHz, CD3COCD3)6 3.44 (d, J = 4 Hz,1H), 3.03 (m, 1H), 1.3-1.6 (m, 16 HI, 0.9 (t, J = 8 Hz, 3 H), 0.2 (s,9 H); EIMS m/z (re1 intensity) 267 (M+ + 1,2), 265 (M+ - 1,l),251 (7), 193 (6); 110 (14), 95 (35), 73 (SiMe3*+,LOO); IR (neat) 2950 (e), 2150 (m), 1250 (s), 840 (s), 760 (m) cm-'. Anal. Calcd for C1&OSi: C, 72.11; H, 11.35. Found C, 72.34, H, 11.15. 3-Methyl-3-phenyl-2-[(trimethyleilyl)ethynyl]oxirane (llj): 220 mg, 96%: l l j (cis isomer) colorless liquid 'H NMR (200 MHz, c&) 6 7.46 (m, 2 H), 7.16 (m, 3 H), 3.30 (a, 1H), 1.36 (8, 3 H), 0.05 (e, 9 H); llj' (trans isomer) 7.10-7.20 (m, 5 H), 3.24 (8, 1H), 1.81 (s,3 H), 0.20 (s,9 H); EIMS m/z (re1 intensity) 231 (M+ + 1,17), 230 (M+,60),229 (M+- 1,30),215 (M+-CH3, 100), 159 (13), 104 (31), 95 (15), 73 (39); IR (film)3050 (w), 2950 (m), 2160 (m),1250 (s), 850 (s), 760 ( 8 ) cm-'; HRMS m/z calcd for C14H160Si230.1127, found 230.1126. 3,3-Diphenyl-2-[(trimethylsilyl)eth~nyl]oxirane(1lk): 234 mg, 80%; pale yellow liquid; 'H NMR (90 MHz, CD3COCD3)6 7.30-7.24 (m, 10 HI,3.12 (e, 1HI,0.03 (e, 9 H); 8IMS m / 2 (re1 intensity) 292 (M+, loo), 277 (29), 165 (36), 105 (55), 73 (8); IR (neat) 3050 (w), 2950 (m), 2150 (m),1250 (s), 840 (e), 760 (e) cm-'; HRMS m/z calcd for ClsHmOSi 292.1260, found 292.1257.
+
Acknowledgment. We are grateful for financial support from the National Natural Science Foundation of China and the Science Foundation of Academia Sinica.
